(1) Field of the Invention
This invention relates to a control device for a vehicle engine which is equipped with an output-controlling throttle valve in the intake passage thereof.
(2) Description of the Prior Art
A throttle valve interposed in the intake passage of an engine is conventionally driven by means of a wire connected to the accelerator pedal.
Throttle valve controlling devices of such a conventional direct-coupled and direct-drive type (mechanical linkage type) as mentioned above are however accompanied by such problems as poor responsiveness due to play in their wires and a poor accelerator pedal feeling due to twisting, corrosion and the like of their wires.
On the other hand, it has been proposed to actuate a throttle valve by using the position of its associated accelerator pedal as an input signal as described in U.S. Pat. No. 4,519,360.
In each of these prior art techniques, however the degree to which the throttle valve is opened is nevertheless designed to correspond directly to the degree to which its associated accelerator pedal is depressed, thereby failing to improve the drivability of the vehicle and the like to any sufficient extent.